ELR Citation: ELR 20303
No(s). 02-1135 (D.C. Cir. Dec 19, 2008)

The D.C. Circuit vacated U.S. Environmental Protection Agency (EPA) rules exempting major sources of air pollution from normal air emissions standards during periods of startups, shutdowns, and malfunctions (SSM) and imposing alternative, less onerous requirements in their place. EPA argued that the general-duty requirement—a source's obligation to minimize emissions to the greatest extent possible—during SSM events is a lawful interpretation of the statute and a reasonable way to reconcile the need to minimize emissions with the inherent technological limitations during SSM events. But the general duty that applies during SSM events is inconsistent with the plain text of Clean Air Act (CAA) §112. Even if "continuous" for purposes of the definition of "emission standards" under CAA §302(k) does not mean "unchanging," the SSM exemption violates the CAA's requirement that some §112 standard apply continuously. The court rejected EPA's argument that it has discretion to make reasonable distinctions concerning those particular activities to which the emission limitations in a maximum achievable control technology standard apply. EPA may not construe the CAA in a way that completely nullifies textually applicable provisions meant to limit its discretion.